In recent years, ScAlMgO4 has attracted attention as a substrate for forming gallium nitride (GaN). ScAlMgO4 has a lattice mismatch with GaN of about 1/10 that of conventional sapphire, and is expected as a material for an increase in brightness of a light-emitting diode (LED).
The Czochralski method (hereinafter, also referred to as the “CZ method”) is known as a method for producing a ScAlMgO4 single crystal. The CZ method is a method including loading a material into a crucible disposed in a chamber, melting the material and then bringing a seed crystal into contact with a melt, and pulling the seed crystal with slow rotation by use of a pulling mechanism. According to the method, a single crystal having the same orientation as that of the seed crystal can be grown, and a cylindrical ingot can be obtained. Japanese Patent Application Laid-Open No. 2015-48296 and Japanese Patent Application Laid-Open No. 2017-119597 each describe a method for producing ScAlMgO4.